Yellow Fever, no not malaria, (that’s different) is a viral disease carried from person to person by female Aedes aegypti mosquitoes. These mosquitoes are just out here to get us huh? Historically, Yellow Fever has had a track record of being one of the most dangerous as well as deadly mosquito borne-diseases to wreak havoc across tropical countries.
So what is yellow fever?
Getting right into it, Yellow Fever is a disease of relatively short duration that traces its origins back to central Africa. Spread by mosquitoes, it affects humans, other apes, and several types of mosquitoes. It is an RNA virus and belongs to the genus Flavivirus. In the early stages, yellow fever is more or less indistinguishable from other illnesses, thus a blood test is required to diagnose a suspected case.
Tracing the history of yellow fever
Now getting into the juicy part, (we can feel the history nerds getting excited) originating somewhere in East or Central Africa, where the transmission of yellow fever first happened from apes to humans, it soon spread to the west. Interestingly, most populations of Africans became immune to the virus due to yellow fever’s prolonged exposure to them throughout their childhoods.
The poor Europeans though, for when they began colonizing these regions, yellow fever outbreaks would ravage their settlements and decimate their populations while the locals were barely affected.
When slaves began to be shipped to the Americas, they brought the disease along with them and soon deadly outbreaks followed, wiping out towns and villages. Symptoms of yellow fever were much harsher on the ancient Mayans who called the virus, “blood vomit.” Sheesh!
Symptoms of yellow fever
- Early symptoms (Acute phase)
- Yellow fever usually begins after an incubation period of three-six days.
- Most cases only cause a mild infection with fever, headaches, chills, back pain, fatigue, and loss of appetite, muscle pain, nausea, and vomiting.
- In these cases, the infection lasts only three to four days. (So consider yourself lucky)
After the acute phase is over, symptoms will begin to go away. Many people recover from yellow fever at this stage, although around 15% of individuals will develop a more serious version of this condition.
- Late stage symptoms (Toxic phase)
- That 15% of individuals later begin to experience recurring fevers, jaundice due to liver damage as well as abdominal pain.
- Bleeding in the mouth, the nose, the eyes, and the gastrointestinal tract cause vomit containing blood, so the Mayans were definitely onto something very macabre.
- There may also be kidney failure, hiccups, and delirium.
Among those who develop jaundice, the fatality rate is 20-50% while the overall fatality rate is 3-7.5% severe cases may have a mortality rate greater than 50%. Luckily, surviving the yellow fever infection provides lifelong immunity and usually results in no permanent organ damage.
Who is at risk for yellow fever?
Yellow fever is a viral disease you can be vaccinated against, therefore it is preventable. People and communities living in regions populated by infected mosquitoes are at risk. These still constitute up to 200,000 active cases each year.
Most cases of yellow fever occur in 32 countries centered in Africa with the worst affected in the following countries;
- Sierra Leone
Due to the 17th-century trans-Atlantic slave trade and the subsequent shipments of slaves to South America, the viral disease is even today widespread in these Latin American countries;
Traveling to many of these countries requires the individual to vaccinate themselves against the disease many days in advance.
How is yellow fever prevented?
For now, vaccination is the only way to stay safe from the disease. The vaccine for yellow fever is given as a single shot. One-shot also lasts a lifetime.
The vaccine is also considered extremely safe. Certain side effects may include:
- A mild headache
- Muscle pain
- A low-grade fever
Other methods of prevention include using insect repellants, wearing clothing to reduce the number of mosquito bites, and staying inside during peak times when insects bite.
Now, when it comes to treating yellow fever, there isn’t much one can do. As yellow fever does not have a cure, it can only be treated by managing symptoms and assisting your immune system in fighting off the infection using the following methods;
- Getting enough fluids, possibly through your veins.
- Getting oxygen
- Maintaining a healthy blood pressure
- Getting blood transfusions
- Having dialysis if you experience kidney failure
- Getting treatment for other infections that may develop
Current status of things
This viral tropic-thriving disease that spread like wildfire throughout the new world was the first human virus to be isolated. With great medical advancements, vector control, and strict vaccination programs, successive South American governments have been able to bring it under control. African nations on the other hand have not seen this much success.
Throughout Africa, governments choose to be dependent upon vaccinations for their virus eradication programs. Because outbreaks usually work in cycles, this program has failed to achieve its objectives. Fewer nations are setting up concerted efforts which in turn increases the likelihood of yellow fever outbreaks to happen more frequently and spread even farther.
Having said this, efforts by the United Nations and other health organizations have helped set up necessary vaccine infrastructure to combat the deadly disease. This helps in the long run as vaccines and health workers can be rushed out to rural areas when a yellow fever outbreak occurs.
From decimating European settlements to being the cause of massive medical expenditure and subsequent advancements through vaccine research to killing 30,000 individuals every year, Yellow Fever has had a turbulent history and disconcerting presence. Hopefully, the future looks dim for this viral disease and bright for us having eradicated it through vaccine efforts, vector control, increased sanitation, better living standards, and a general sense of awareness.